How the Brain Works

Disclaimer: This information sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

The brain is part of the central nervous system which includes the brain, the brain stem, the cerebellum and spinal cord. The brain is made up of nerves that are cells that send and receive electrical impulses to and from the body.

If you take a close look at a human brain, you'll find it has three main parts. By far, the largest is the cerebrum on top. The surface of the cerebrum is called the cerebral cortex. Although less than 0.5cm thick, the cerebral cortex is critical to your child's ability to move, to understand what they see and hear, and to do the complex process called thinking - making decisions, learning, remembering, and planning. The cerebrum is divided into two halves, called hemispheres. Each has specialised functions. An "electric highway" of nerve fibres, the corpus callosum, connects the two, allowing information to pass between them. Hemispheres are further divided into smaller parts called lobes; the frontal, temporal, parietal and occipital lobes. In focal brain injury, just one lobe in one hemisphere may be affected. In diffuse injury, all lobes of both hemispheres may be affected.

Figure 1 The Brain Areas

At the back of your brain and beneath the cerebral cortex is the cerebellum. This coordinates skilled movement, giving your child the ability to walk without stumbling, and use their hands smoothly and precisely.

Located at the base of the brain is the brain stem, a stalklike structure that connects it to the spinal cord. The brain stem takes care of basic, involuntary functions, such as breathing, blinking and bowel regulation.

What are the effects of injury to the different areas of the brain?

Frontal lobes - the frontal lobes control most complex functions, which are referred to as executive functions . These include planning, control of impulses, initiation, attention and emotion (see cognitive section and behaviour section). The back of the frontal lobe also controls movement of the opposite side of the body. Damage to the frontal lobes may cause changes in behaviour, attention, emotions and also weakness to the opposite side of the body. See information sheets.

Parietal lobes - the parietal lobes provide sensory information to the brain, including touch, pain and temperature. Damage may cause the child to lose sensation down the opposite side of the body. This may result in the child being less aware of parts of their body (sensory neglect).

Temporal lobes - the functions of the temporal lobes include hearing, memory and learning. Damage may cause difficulties with organising what to say, and finding and using the correct words. It may also result in difficulties with short-term memory. See information sheets.

Occipital lobes - the occipital lobes help us understand what we see. They interpret the colour, shape and distance of what we look at. Damage may result in a distortion of what is seen and difficulty recognising or interpreting familiar objects. See eyes and vision.

Cerebellum - damage to this area may result in movement becoming jerky or uncoordinated known as cerebellar ataxia. The child's speech may also become slurred and difficult to understand. See www.wemove.org/kidsmove/ata

Rehabilitation Department The Children's Hospital at Westmead Cnr Hawkesbury Rd & Hainsworth St, Westmead Locked Bag 4001, Westmead, 2145 Tel: (02) 9845 2132 - Fax: (02) 9845 0685 http://www.chw.edu.au/rehabilitation/